Apparatus for supplying water to concrete mixers



Feb. 27, 1934. I c F. L 1,949,364

APPARATUS FOR SUPPLYING WATER TO CONCRETE MIXERS Filed Jan. 18, 1930 2 Sheets-Sheet 1 Feb. 27, 1934. B LL 1,949,364

APPARATUS FOR SUPPLYING WATER TO CONCI RETE MIXERS Filed Jan. 18, 1930 2 Sheets-Sheet 2 TNVENTOR. CharZesFfiall,

ATTO NEYJ' Patented Feb 27, 1934 retest-i rar GFFICE APPARATUS FOR SUPPLYING WATEE Till C(DNGREEE MEXERS Charles halt, Milwaukee, Wis., assigncr to Chain Belt @ompeimy, Milwaukee, Wis., a corporation oi Wisconsin Application .Fanuary is, 1930. Serial No. 421,783

1 Claim.

This invention relates to a method of and apparatus for supplying water to concrete mixers and more especially to a transit concrete mixer and has for one of its objects to improve the d methods and apparatus heretofore proposed for this purpose.

In the operation of contractors mixers and paving mixers, which are usually stationary for considerable periods of time as distinguished ill from the so called transit mixers, it usually happens that the ingredients for mixing a batch of concrete are introduced into the mixer drum immediately after the discharge of the previous batch, so that little time is afforded for those portions of the said previous batch which unavoidably adhere to the surfaces of the drum and mixing blades to harden thereon. On the other hand, where in the operation of such mixers, for some reason or other a delay occurs in the introduction of a new batch of materials into the drum after the discharge of a preceding batch, it has been common practice for the op-' erator to introduce a quantity of water into the drum and to keep it rotating until the fresh batch of materials is ready, so as to prevent the hardening of the adhering portions of the preceding mix on the drum surface-and blades.

In the use of transit mixers wherein a consid erable period of time necessarily elapsed between the discharge of each batch of mixed concrete and the introduction of a new batch of material intothe drum, it has been previously proposed to introduce a quantity of wash water into the drum after the discharge of each batch of concrete and t6 retain this wash water in the drum during the introduction and mixing of the next succeeding batch of material. Ordinarily this wash water is not sufiicient in quantity to completely hydrate the cement of the succeed ing batch but an additional amount of water is added to bring the total up to that necessary for complete hydration.

In these said prior devices, however, no provision is made for the accurate control of the amount of wash water introduced into the drum, it being left largely to the volition of the operator as to just how much water is left in the water carrying tank for wash purposes after the required amount for the completion of the preceding mix has been withdrawn therefrom. In view of the now generally accepted water-cement ratio theory under which the accurate control of the amount of water added to the solid materials is of prime importance, it becomes very desirable to not only accurately gauge the major portion of the water introduced intothe drum but also the amount employed for wash purposes, and it is one of the principal objects of the present invention to provide an apparatus and method whereby the total water, including 0 that used for washing purposes, may be readily and accurately controlled.

It is a further object of the invention to provide an apparatus wherein the amount of wash water will always remain a fixed definite quantity, whereas the additional amount of water necessary to bring thetotal up to that required for a particular mix may be readily varied at will.

With the-ab ove'and other objects in view which will appear as the description proceeds, the invention -consists of the novel details of construction and combinations of parts constituting the apparatus, and in the novel steps and combinations of steps constituting the method, all as will N be more fully disclosed below and particularly pointed out in the claim.

Referring to the accompanying drawings 1'0rm-. ing a part of this specification, in which like reference characters designate like parts mall the '0 views:-

Figure 1 is a side elevational view 01' a conventional form of transit mixer embodying the apparatus constituting a portion or the present invention;

Figure 2 is an enlarged elevational view partly broken away of a water measuring and supply tank for the transit mixer shown in Figure 1; and

Figure 3 is an enlarged cross-sectional view partly broken away of the parts shown in Figure 2.

Referring more particularly to the said drawings, the transit mixer comprises a truck chassis 10 conventionally shown, upon which is mounted the rotatable mixing drum 11 which may be driven through a chain 12 from an independent motor 13 all as is disclosed in my co-pendingapplication Ser. No. 346,988, filed March 14, 1929 entitled Concrete mixers and agitators now Patent No. 1,781,965, dated November 18, 1930. 10

The water tank 15 which constitutes a portion of the present invention may be mounted upon any suitable support 16 and is provided with an internal partition wall or plate 17, which divides it into a larger or main compartment 18 and a smaller compartment 19. The said compartment 19 constitutes the wash water compartment, which is always completely filled at the beginning of each trip so that a certain predetermined fixed quantity of water is always supplied thereby to pear more fully below.

The main compartment 18 is intended to receive and hold the principal portion of the water employed for each batch of concrete, and since it is frequently desirable to vary the quantity of water used, either for the purpose of changing the consistency of the mix, or for enabling larger or smaller quantities of concrete to be mixed, means are provided whereby the quantity of water carried in this compartment may be readily controlled by the operator.

As herein shown this means comprises a vertically slidable overflow tube or pipe 20 which passes through a. stufling box or gland 21 in the wall of the tank and is provided at its lower end with a valve 22. A fixed gauge rod 23 is associated with the said pipe so that by means of an indicator 24 carried by the pipe 20 the latter may be adjusted to permit the retention in the chamber 18 of any predetermined quantity of water.

The chamber 19 is provided with a suitable filling hatch 25 and likewise the chamber 18 is provided with a filling hatch 26 through which hatches the water may be introduced as required. Discharge pipes 27 and 28 lead from the chambers 18 and 19 respectively, being controlled by valves 29 and 30 and joining at 31 to a common discharge pipe 32. This said pipe 32 which is stationary is connected by means of a suitable slip joint 33 with a pipe 34 extending through and carried by one end wall of the mixer drum 11 at substantially its rotating axis. The said pipe 34 is journalled in a suitable bearing 35 and constitutes the support for the said end of the drum. At its discharge end it is preferably provided with a suitable valve structure 36 which will permit the discharge of water therefrom into the interior of the drum but which will prevent the solid materials from working their way back into the pipe 34 where they might collect and harden, thereby clogging the said pipe.

In use the compartment 19 is completely filled with water, usually at the time the solid materials are being introduced into the drum 11 at the central plant or batch hopper, it having been previously determined as to the total quantity of water which will be necessary for a particular batch of concrete; and the capacity of the compartment 19 being known, the adjustable pipe 20 is moved so that the quantity of water which may be introduced and retained in the compartment 18 will be the difference between the total amount required and that in the wash water compartment 19.

At the beginning of operation, for the fir batch, the quantity of water introduced into the compartment 18 may be the total necessary for the batch, since there will be no wash water in the drum at that time. However, for each succeeding batch the water carried in the compartment 18 will be the difierence between the total amount and the capacity ofthe compartment 19.

After the discharge of the completed batch from the drum at the place where it is to be used, the operator then opens the valve 30 and permits the water in the compartment 19 to fiow into drum which may be slowly revolved upon the return trip of the mixer so as to prevent the hardening of the concrete upon the inner drum surface. When the mixer reaches the central plant the compartments 18 and 19 are refilled while the solid materials are being introduced into the drum, thecompartment 19 being completely filled and the necessary adjustments made in the overflow pipe 20, if it is desired to change the total quantity of water supplied to the succeeding batch. After the drum has been loaded the mixer begins its return trip to the work and the water from the compartment 18 is introduced at any desired time during the return trip, and the batch mixed. The total water introduced for each batch will be the quantity contained in the compartment 18 (which as above described may vary according to the requirements) plus the fixed amount carried in the wash water compartment 19, which always remains the same.

It will thus be seen that the present invention provides means whereby a definite fixed amount of wash water may be introduced into the mixer drum after each mixing operation, which wash water remains in the drum and becomes a part of the water required for the succeeding batch; and that the additional quantity of water required for each particular batch may be added. which additional quantity may be readily varied at will so that the total may be accurately controlled.

It is obvious that those skilled in the art may vary the details of construction constituting the apparatus, as well as the steps constituting the method, without departing from the spirit of the invention and, therefore, it is not wished to be limited to the above disclosureexcept as may be required by the claim.

What is claimed is:

In a water supply apparatus for concrete mixers, a receptacle provided with a partition wall dividing it into two compartments, one of which is adapted to receive and hold a predetermined fixed quantity of wash water; means comprising an adjustable overfiow pipe and a gauge rod associated with the other compartment for varying at will the quantity of water contained therein; a common discharge pipe leading from said compartments to the mixer drum; and a valve in said pipe adjacent each compartment, whereby said compartments may be discharged simultaneously or separately as desired.

CHARLES F. BALL. 

